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+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group. *
+ * All rights reserved. *
+ * *
+ * This file is part of HDF5. The full HDF5 copyright notice, including *
+ * terms governing use, modification, and redistribution, is contained in *
+ * the COPYING file, which can be found at the root of the source code *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases. *
+ * If you do not have access to either file, you may request a copy from *
+ * help@hdfgroup.org. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created: atomic_writer.c
+ *
+ * Purpose: This is the "writer" part of the standalone test to check
+ * atomic read-write operation on a system.
+ * a) atomic_writer.c--the writer (this file)
+ * b) atomic_reader.c--the reader
+ * c) atomic_data--the name of the data file used by writer and reader
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/***********/
+/* Headers */
+/***********/
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if !defined(WIN32) && !defined(__MINGW32__)
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+/****************/
+/* Local Macros */
+/****************/
+
+#define FILENAME "atomic_data"
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+static void usage(void);
+
+
+/*-------------------------------------------------------------------------
+ * Function: usage
+ *
+ * Purpose: To print information about the command line options
+ *
+ * Parameters: None
+ *
+ * Return: void
+ *
+ *-------------------------------------------------------------------------
+ */
+static void
+usage(void)
+{
+ printf("\n");
+ printf("Usage error!\n");
+ printf("Usage: atomic_writer -n <number of integers to write> -i <number of iterations for writer>\n");
+ printf(" Note**The number of integers for option n has to be positive\n");
+ printf(" Note**The number of integers for option i has to be positive\n");
+ printf("\n");
+} /* usage() */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function: main
+ *
+ * Purpose: To write a series of integers to a file for the reader to verify the data.
+ * A write is atomic if the whole amount written in one operation is not interleaved
+ * with data from any other process.
+ * (1) Iterate with i iterations
+ * (2) Write a series of integers (0 to n-1) to the file with this pattern:
+ * offset 0: 0000000000000000000000000000000
+ * offset 1: 111111111111111111111111111111
+ * offset 2: 22222222222222222222222222222
+ * offset 3: 3333333333333333333333333333
+ * ...
+ * ...
+ * offset n-1: (n-1)
+ *
+ * At the end of the writes, the data in the file will be:
+ * 01234567........(n-1)
+ *
+ * Note:
+ * (a) The # of integers (via -n option) used by the writer and reader should be the same.
+ * (b) The data file used by the writer and reader should be the same.
+ *
+ * Future enhancement:
+ * 1) Provide default values for n and i and allow user to run with either 0 or 1 option
+ * 2) Use HDF library HD<system calls> instead of the system calls
+ * 3) Handle large sized buffer (gigabytes) if needed
+ *
+ * Return: Success: EXIT_SUCCESS
+ * Failure: EXIT_FAILURE
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+main(int argc, char *argv[])
+{
+ int fd = -1; /* file descriptor */
+ ssize_t bytes_wrote; /* the nubmer of bytes written */
+ unsigned int *buf = NULL; /* buffer to hold written data */
+ unsigned int n, u, i; /* local index variable */
+ int temp; /* temporary variable */
+ unsigned int iterations = 0; /* the input for "-i" */
+ unsigned int num = 0; /* the input for "-n" */
+ int opt = 0; /* option char */
+
+ /* Ensure the # of arguments is as expected */
+ if(argc != 5) {
+ usage();
+ exit(EXIT_FAILURE);
+ } /* end if */
+
+ /* Parse command line options */
+ while((opt = getopt(argc, argv, "n:i:")) != -1) {
+ switch(opt) {
+ case 'n':
+ if((temp = atoi(optarg)) < 0) {
+ usage();
+ exit(EXIT_FAILURE);
+ } /* end if */
+ num = (unsigned int)temp;
+ break;
+ case 'i':
+ if((temp = atoi(optarg)) < 0) {
+ usage();
+ exit(EXIT_FAILURE);
+ } /* end if */
+ iterations = (unsigned int)temp;
+ break;
+ default:
+ printf("Invalid option encountered\n");
+ break;
+ } /* end switch */
+ } /* end while */
+
+ printf("WRITER: # of integers to write = %u; # of iterations = %d\n", num, iterations);
+
+ /* Remove existing data file if needed */
+ if(remove(FILENAME) < 0) {
+ if(errno == ENOENT)
+ printf("WRITER: remove %s--%s\n", FILENAME, strerror(errno));
+ else {
+ printf("WRITER: error from remove: %d--%s\n", errno, strerror(errno));
+ goto error;
+ } /* end else */
+ } else
+ printf("WRITER: %s is removed\n", FILENAME);
+
+ /* Create the data file */
+ if((fd = open(FILENAME, O_RDWR|O_TRUNC|O_CREAT, 0664)) < 0) {
+ printf("WRITER: error from open\n");
+ goto error;
+ } /* end if */
+
+ /* Allocate buffer for holding data to be written */
+ if((buf = (unsigned int *)malloc(num * sizeof(unsigned int))) == NULL) {
+ printf("WRITER: error from malloc\n");
+ if(fd >= 0 && close(fd) < 0)
+ printf("WRITER: error from close\n");
+ goto error;
+ } /* end if */
+
+ printf("\n");
+
+ for(i = 1; i <= iterations; i++) {
+ printf("WRITER: *****start iteration %u*****\n", i);
+
+ /* Write the series of integers to the file */
+ for(n = 0; n < num; n++) {
+
+ /* Set up data to be written */
+ for(u=0; u < num; u++)
+ buf[u] = n;
+
+ /* Position the file to the proper location */
+ if(lseek(fd, (off_t)(n*sizeof(unsigned int)), SEEK_SET) < 0) {
+ printf("WRITER: error from lseek\n");
+ goto error;
+ } /* end if */
+
+ /* Write the data */
+ if((bytes_wrote = write(fd, buf, ((num-n) * sizeof(unsigned int)))) < 0) {
+ printf("WRITER: error from write\n");
+ goto error;
+ } /* end if */
+
+ /* Verify the bytes written is correct */
+ if(bytes_wrote != (ssize_t)((num-n) * sizeof(unsigned int))) {
+ printf("WRITER: error from bytes written\n");
+ goto error;
+ } /* end if */
+ } /* end for */
+
+ printf("WRITER: *****end iteration %u*****\n\n", i);
+
+ } /* end for */
+
+ /* Close the file */
+ if(close(fd) < 0) {
+ printf("WRITER: error from close\n");
+ goto error;
+ } /* end if */
+
+ /* Free the buffer */
+ if(buf)
+ free(buf);
+
+ return EXIT_SUCCESS;
+
+error:
+ return EXIT_FAILURE;
+} /* end main() */
+
+#else /* WIN32 / MINGW32 */
+
+int
+main(void)
+{
+ printf("Non-POSIX platform. Exiting.\n");
+ return EXIT_FAILURE;
+} /* end main() */
+
+#endif /* WIN32 / MINGW32 */
+
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